The present invention relates to a method of fabricating a nanostructure, comprising the following steps: prestructuring a substrate (1) adapted to receive the nanostructure to form a nanorelief (2) on the substrate, the nanorelief having flanks (4) extending from a bottom (1a) of the substrate and a top face (3) extending from said flanks, and then depositing on the substrate pre-structured in this way a single layer or multilayer coating intended to form the nanostructure; and further comprising: adding to the prestructured substrate or to the coating a separation layer adapted to enable separation of the coating and the substrate by external action of mechanical, thermomechanical or vibratory type; and exerting this external action on the substrate and/or the coating to recover selectively a top portion of the coating by separating it from the top face of the nanorelief so that this top portion constitutes some or all of the nanostructure.